Derivation of nutritional threshold values from cumulative concentration distributions

For many tree species nutritional threshold values are not available. Because the derivation of such values by fertilization experiments would be very time consuming and cost intensive a relatively easy method is proposed. By interpreting cumulative concentration distributions the thresholds for the range of normal nutrition as well as the threshold for deficiency can be deduced. As shown for the species spruce, pine and beech this method delivers values, which are in most cases very close to the known thresholds from literature. Provided that a suitable data set exists or can be set up the proposed procedure can be used to derive nutritional thresholds for species for which up to now no such values are available.